The number of television programs that a viewer may receive at any given time has increased geometrically in the last few years. Conventional analog television systems such as those conforming to the National Television Standards Committee (NTSC) and Phase Alternate Line (PAL) standards transmit one program per six MHz or eight MHz channel. Recently, digital television signal processing techniques have been developed that allow multiple programs to be transmitted in each six MHz channel. Furthermore, there are now many sources of television signals in addition to the conventional broadcast antenna. A viewer may receive television signals via wired cable systems, several different types of satellite systems, so-called wireless cable systems and, in the near future, via a global information network, such as the Internet.
Conventional cable television systems are capable of delivering at least 140, six MHz channels and some systems are capable of delivering over 200 channels via a coaxial cable. Presently, new technology is being investigated to increase the number of programs that can be delivered to the home. This is being done via two technologically strategic moves. The first is to increase the allocated bandwidth to one GHz (which provides for 150, six MHz channels). The second is to use video compression to configure a channel to carry up to ten minor channels in one six MHz channel. Channels that include a plurality of minor channels are also known as multiprogram channels. Typical numbers that are used in the industry estimate that about 500 programs can be delivered to the home over a single coaxial cable. Fiber optic cable provides many times the bandwidth of a coaxial cable and promises to be able to provide several thousand programs. In the same way, increased bandwidth for satellite systems may allow a viewer to receive upwards of one-thousand six MHz channels, each channel containing up to ten minor channels.
It is difficult, however, for a viewer to sort through this large number of programs. Problems are already being felt where subscribers searching through 140 programs, much less 500 or 1000. To address this problem, many of the newer television systems have on-screen menus that present the program selections organized by type. One such system uses a dedicated channel to display program schedule information. To view the information, the viewer simply tunes to the dedicated channel. The advantage of such a system is that it is relatively easy to deploy because it is centrally implemented at the transmission head-end. No additional electronics or software is required at the viewer location because full control of the display is maintained at the transmission head-end. The display information is then broadcast continuously on a dedicated channel. The television viewer simply tunes the cable converter box or television tuner to the channel on which the schedule information is displayed to view the program listings. Typically, these program guides utilize a scrolling display of television listings. Some systems employ a partial screen of listings with additional information in the remainder of the screen such as advertisements for movies on pay channels, pay-per-view event schedules, time and weather information, and other commercial information. These systems generally incorporate a grid or matrix to display the program schedule information, with a different row for each channel and columns representing different time slots.
Another type of electronic program guide uses software and/or hardware in the viewer's receiver to retrieve and process a television schedule database that is transmitted during a portion of a television channel (e.g. the vertical blanking interval). One such system is the Starsight™ service. A television receiver equipped to use the Starsight service periodically tunes to a guide channel, even when the receiver is turned off, to recover a schedule information database that is encoded in the vertical blanking interval of the television signal that is sent over the guide channel. The system then formats the data so that it may be displayed to the viewer as a hierarchical set of on-screen menus. These menus allow the user some flexibility in determining how the data is displayed. For example, program data may be displayed by type of program (e.g. sports, drama, comedy). Alternatively the viewer may select only a few favorite channels for which data are displayed.
Even with this amount of interaction, existing electronic program guide (EPG) systems may be frustrating for a viewer, especially one who has access to a large number of channels, because only a relatively small number (e.g. ten) can be viewed at any one time. If, for example, a viewer is connected to a fiber optic cable system or to a combination of a broadcast antenna, satellite dish and cable system and can receive 500 to 1000 programs, 50 to 100 screens would be needed to display all of the possible options. In addition, existing EPG systems are still somewhat difficult to use and lack features that may make them aesthetically pleasing. These deficiencies contribute to their limited use by viewers and general preference for printed television schedules.
In addition, many viewers may find a continuously scrolling program guide difficult to read because their eyes must follow the listings as they move up the screen. Compounding this problem is the tendency to use scrolling listings in a split screen format together with advertisements, promotional information and other information. It may be frustrating for viewers to be forced to continuously view this information while they are waiting for the schedule information for a desired channel to appear on the display.
Another possible reason why electronic program guides are under-utilized is they simply are boring to watch. While a full screen of listings allows for the display of more schedule information at one time and thus a shorter cycle time through the entire program schedule, viewers could be bored by the monotony of continuously viewing a full screen of listings. As indicated above, however, split screen program guides that simultaneously display additional information of possible interest to the viewer have the disadvantage of much longer cycle times.
A further possible reason why electronic program guides are under utilized is that viewers simply are not interested in many of the available programs. Many viewers limit their primary viewing to selected categories or programs.
Effective menu systems, however, are a requirement in the age of digital television. Due, in part, to the compression techniques used to encode up to ten standard definition television (SDTV) programs into one six MHz channel, switching among channels takes much more time on a digital receiver than on an analog receiver. It may take, for example, three or four seconds between the time the viewer selects a new program and the time any image information for that program is displayed on the receiver.
Accordingly, there exists a need for an improved technique of displaying program information in order to make program schedule grids more readable and manageable. There also exists a need for providing a more aesthetically pleasing display environment for the program schedule information, and more flexible display formats. There is also a particular need for a display system that can efficiently provide the above for a system comprising several hundred to several thousand channels.